MAX8834Y Datasheet, PDF (1/43 Pages) Maxim Integrated Products – Adaptive Step-Up Converters with 1.5A Flash Driver

19-4421; Rev 0; 4/09
EVAALVUAAILTAIOBNLEKIT
Adaptive Step-Up Converters
with 1.5A Flash Driver
General Description
The MAX8834Y/MAX8834Z flash drivers integrate a
1.5A PWM DC-DC step-up converter and three pro-
grammable low-side, low-dropout LED current regula-
tors. The step-up converter features an internal
switching MOSFET and synchronous rectifier to
improve efficiency and minimize external component
count. An I²C interface provides flexible control of step-
up converter output voltage setting, movie/flash mode
selection, flash timer duration settings, and current reg-
ulator settings. The MAX8834Y/MAX8834Z operate
down to 2.5V, making them future proof for new battery
technologies.
The MAX8834Y/MAX8834Z consist of two current regula-
tors for the flash/movie mode. Each current regulator can
sink 750mA in flash mode and 125mA in movie mode.
The MAX8834Y/MAX8834Z also integrate a 16mA low-
current regulator that can be used to indicate camera
status. The indicator current regulator includes program-
mable ramp and blink timer settings. A programmable
input current limit, invoked using the GSMB control,
reduces the total current drawn from the battery during
PA transmit events. This ensures the flash current is set
to the maximum possible for any given operating condi-
tion. Additionally, the MAX8834Y/MAX8834Z include a
MAXFLASH* function that adaptively reduces flash cur-
rent during low battery conditions to help prevent system
undervoltage lockup.
Other features include an optional NTC input for finger-
burn protection and open/short LED detection. The
MAX8834Y switches at 2MHz, providing best overall
efficiency. The MAX8834Z switches at 4MHz, providing
smallest overall solution size. The MAX8834Y/
MAX8834Z are available in a 20-bump, 0.5mm pitch
WLP package (2.5mm x 2.0mm).
*Patent pending.
Ordering Information
PART
TEMP
PIN-PACKAGE
SWITCHING
FREQUENCY
RANGE
(MHz)
MAX8834YEWP+T ^{-40°C to 20 WLP}
2
+85°C (2.5mm x 2.0mm)
MAX8834ZEWP+T
-40°C to
+85°C
20 WLP
(2.5mm x 2.0mm)
4
+Denotes a lead(Pb)-free/RoHS-compliant package.
T = Tape and reel.
Pin Configuration appears at end of data sheet.
Features
♦ 2.5V to 5.5V Operation Range
♦ Step-Up DC-DC Converter
1.5A Guaranteed Output Current
Adaptive or I²C Programmable Output Voltage
2MHz and 4MHz Switching Frequency Options
♦ Two Flash/Movie LED Current Regulators
I²C Programmable Flash and Movie Current
Low-Dropout Voltage (110mV max) at 500mA
♦ LED Indicator Current Regulator
I²C Programmable Output Current
Ramp and Blink Timers for Indicator Mode
Low-Dropout Voltage (130mV max) at 16mA
♦ I²C Programmable Safety and Watchdog Timers
♦ GSM Blank Logic Input
♦ MAXFLASH System Lockup Protection
♦ Remote Temperature Sensor Input
♦ Open/Short LED Detection
♦ Thermal Shutdown Protection
♦ < 1µA Shutdown Current
♦ 20-Bump, 0.5mm Pitch, 2.5mm x 2.0mm WLP
Applications
Cell Phones and Smart Phones
PDAs, Digital Cameras, and Camcorders
Typical Operating Circuit
INPUT
2.5V TO 5.5V
10μF
1μH OR 2.2μH
LX
IN
AGND
PGND
COMP
MAX8834Y
MAX8834Z
PROGRAMMABLE
OUTPUT
3.7V TO 5.2V
OUT
10μF
FLED1
FLED2
1.5A TOTAL
FLASH
PA_TXON
FLASH ON
I²C
VLOGIC
0.1μF
GSMB
LED_EN
SCL
SDA
VDD
INDLED
FGND
16mA INDICATOR
NTC
FINGER-BURN
PROTECTION
________________________________________________________________ Maxim Integrated Products 1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.